Counter using beam switching tube with means for disabling carry signal generating means during rest



Feb. 2, 1965 A. SOMLYODY 3,168,675

COUNTER usmc BEAM swmumc TUBE WITH MEANS FOR DISABLING CARRY SIGNAL GENERATING MEANS DURING REST Filed Nov. 19, 1962 TO NEXT COU NTER INVENTOR. ARPAD SOMLYODY ATTORNEY 3,168,675 Patented Feb. 2, 1965 s 168 675 COUNTER UsrNc BEAM swrrcrnnc TUBE Wrrn MEANS Fora .nrsasrmo CARRY SIGNAL GEN- ERATING MEANS nUnrNc ansr Arpad Somlyody, Raritan, N.J., assignor to Burroughs Corporation, Detroit, Mich, a corporation of Michigan Filed Nov. 19, 1962, Ser. No. 238,475 7 Claims. (Cl. 3158.5)

This invention relates to electronic counting circuits and particularly to counting circuits using multi-position magnetron beam switching tubes as the counting elements thereof.

Magnetron beam switching tubes are counting devices which include an electron-emitting cathode and ten groups of electrodes, each of which is adapted to receive an electron beam from the cathode and to provide an output signal therefrom. Each group of electrodes includes a target electrode which receives an electron beam and produces an'output signal therefrom, an auxiliary collector electrode, a spade electrode which forms and holds an electron beam on its associated target electrode,and a switching electrode which may be used to switch an electron beam from one group of electrodes to the next to perform the counting operation. 7

In the operation of magnetron beam switching tubes in counter circuits, a typical multi-stage counter includes a plurality of such tubes connected together in series. Each tube is adapted to perform a counting cycle in which an electron beam switches from position to position, and, when a predetermined last position is reached in atube, a carry pulse is transmitted to the next tube in the counting chain. Under some circumstances, the carry operation is accompanied by the clearing and resetting of an electron beam in a tube which has just completed a counting cycle. In arranging the circuitry to perform the beam clearing and resetting operation and the signal carry operation, problems generallyarise due to the fact that consideration must be given to obtaining an output pulse from the same position from which the carry pulse is generated. In general, it is necessary to prevent the reset pulse itself from operating as a signal carry pulse.

Accordingly, the principles and objects of the present invention. are concerned with the provision of an improved counter usingmagnetron beam switching tubes as the counting units thereof, and having improved circuit means for obtaining a carry signal and for clearing and resetting an electron beam in each tube.

Briefly, a counting circuit embodying the invention includes a multiposition beam switching tube as the counting elenient(s) thereof, with one of the positions of the tube being selected both for the transmission of a carry pulse at the end of a counting cycle and for the resetting of an electron beam after a beam has been cleared and it isdesired to initiate a new counting cycle. A signal generating means is coupledto said one position for generating a carry pulse when an electron beam registers a count in said one position, and auxiliary means is coupled to said signal generating means for disabling said signal generating means during the beam resetting operation. a

In the. drawing, the single figure is a schematic representation of a circuit embodying the invention.

The circuit shown in the drawing is particularly suited for use with magnetron beam switching tubes such as the type 6700 tube and with similar devices sold by'the Burrough Corporation and known as Beam-X switches.

Thesedevices are cylindrical in form, butthey are shown schematically in linear form as tube 10 in FIG. 1. The

, tube 10 has an envelope 12 which contains a central cathode 14 and ten'groups of electrodes spaced radially equidistantly from and surrounding the cathode. For. Vc is coupled through source to cathode 14. The

simplicity, only five groups of electrodes are shown numbered 1, 2, 8, 9, and 0. Each group of electrodes includes a spade-electrode 16 and a target electrode 18, with each spade electrode serving to form and hold an electron beam on its corresponding target electrode which itself provides an output signal from the beam. A switching electrode 20, known. as a switching grid and used for switching an electron beam from position to position, is also included in each group of electrodes. In the Beam-X switch, an auxiliary electrode 22 is provided between each target and the adjacent leading spade, and the auxiliary electrode acts as a current collecting electrode.

The tube 10 also includes'suitable means (not shown) for providing an axial magnetic field whichoperates with electric fields within the tube to form an electron beam In the circuit of thedrawing, each of the spade electrodes 16 except the 0 position spade iscoupl'ed through a spade load resistor 26 to a bus 28, one errd of Whtich is connected to a source of reference potential such as ground. The same spades are also coupled through sepand to ground. It is assumed that. the 0 position is the one at which an electron beam is to be reset and from which a carry pulse is generated. The circuit connections of the 0 spade are described below. Y y r The target electrodes 18 and connected through suitable load resistors 32to the bus 28. In addition, an

auxiliary output tap 34 is provided at each target for, connection to a suitable utilization device or circuit, for

example, the glow cathodes of a 6844A indicator tube, or a printing mechanism or thejlike.

The switching grid electrodes 20 are connected to -a source of counting pulses, and, in one arrangement, the grids at the even-numbered positions are connected together in one set and the grids at the odd-numbered posi-,

tions are connected together in anotherset. Each set of grids is then connected to oneof the outputs of a suitable flip-flop circuit 42 which comprises a source of counting pulses.

According to the invention, anelectron discharge device is provided for generating a carry pulse for transmission for tube 10 to the next counting tube (not shown). One suitable device is a PNP transistor 50 which includes base, emitter, and collector electrodes 54, 55, and 56, respectively. The base electrode of the transistor 50 is connected through spade resistor 26' to the 0 spade, and the emitter electrode 55 is connected to bus 28. A diode 6G, oriented as shown for controlling the transistor base potential, is connected between the emitter 55 and base 54 of transistor .50. The base. electrode is also coupled through a suitable resistor 64 to a source of positive DC. bias potential Vb of. the order of 12 A source 94 of positivev reset pulses is coupled to the cathode 14 of tube 10, anda negative DC. power source potential of V may be about 55 volts which is selected to provide about l2 volts at point 74.

In operation of the circuit of the invention, initially, with no curent flowing to the 0 spade and to the base of transistor 50, the transistor is held off. Point'74 is at about l2 volts, and capacitor St) is charged to the potentialof point 74-. The collector 68 is also at about -12 volts. As beam switching tube It? executes a counting cycle under the influence of counting pulses applied alternately to the two sets of switching electrodes 20 by flip-flop 42, an electron beam moves from position to position in the tube. As the beam flows to each position, an output signal appears at tap 34 of each target electrode.

' When the beam reaches the last position in the counting electrode at the 0 position receives beam current and. drops in potential. This lowered potential applied to the base of the transistor 50 causes the transistor to be turned on, and a positive carry pulse appears at the collector output terminal 68 which rises to about ground potential. This positive pulse is used to drive the next counting tube in the counting chain which thus registers an indication of the fact that the first tube has completed its counting cycle. When the tube 10 executes another counting cycle, a carry pulse is applied to and is registered in the next tube. Generally, the positive carry pulse would be applied to' a flip-flop (not shown) similar to flipflop 42, I

When it is desired to clear an electron beam in tube 10 and reset it at the 0 position, a generally sawtoothwave 95 is applied from source 94 to the cathode 14, and the positive portion thereof raises the cathode to a level at which an electron beam in the tube is cleared. In this case, the cathode is raised to about ground potential to cause the beam to clear. The negative portion of wave' 95 is then coupled through capacitor 90 to the 0 spade, and the beam is then reformed in the 0 position. It is noted that the negative portion of wave 95 is also coupled to the base electrode of transistor 50 which might thus be turned on and caused to generate a spurious carry pulse. However, transistor 50 is prevented from being turned on by the fact, that, when wave 95 raises the cathode to ground potential, the capacitor 80 discharges and point '74 and the collector 56 go to ground potential. With the supply voltage thusremoved from the transistor, it is prevented from being turned on and generating an output carry pulse when the negative portion of the wave 95 is applied through capacitor 90 to the O spade electrode to set a beam at the 0 position.

What isclaimed is:

1. A counter circuit including an electron beam switching tube having a cathode and a plurality of groups of electrodes; each group including a target electrode which receives an electron beam and produces an output signal therefrom, a spade electrode which holds an electron beam on its associated target electrode, and a switching electrode which serves to switch an electron beam from one group of electrodes to the next; a

said cathode being connected to a source of reference for generating a carry pulse when an electron beam registers a count in said one position; and means coupled to saidsignal generating means for disabling said signal generating means during a pulse 5 resetting operation.

2. A counter circuit including an electron beam switching tube having a cathode and a plurality of groups of electrodes; each group including a target electrode which received an electron beam and produces an output signal therefrom, a spade electrode which holds an electron beam on its associated target electrode, and a switching electrode which serves to switch an electron beam from one group of electrodes to the next;

said cathode being connected to a source of reference potential, said spade electrodes being connected through resistive paths to a source of reference potential, said target electrodes being coupled through resistive paths to a source of reference potential, and said switching electrodes being connected to a source of switching signals;

one of the positions being selected both for the transmission of a carry pulse at the end of a counting cycle and for the resetting of an electron beam after a beam has been cleared and it is desired to initiate a new counting cycle; 7

an electron discharge device coupled to said one position for generating a carry pulse when an electron beam registers a count in said one position;

a pulse source coupled both to the cathode of said beam switching tube and to said one position in said tube for clearing and resetting an electron beam in said tube;

and disabling means coupled to said discharge device for disabling it and thus preventing it from generating a carry pulse during a pulse resetting operation.

I The circuit defined in claim 2 wherein said discharge device is a transistor having base, emitter, and collector electrodes,

the base electrode of said transistor being coupled to the spade electrode at said one position in said tube, the emitter electrode being coupled to'a source of reference potential, thecollector electrode being cou plied through a resistive path to the cathode of said beam switching tube,

said pulse source also being coupled to the spade electrode at said one position,

said disabling means being coupled to the cathode of said tube so that when a pulse is applied to said cathode to clear a beam in said tube, said disabling means operates to disable said transistor and prevent it from operating when a pulse is applied to said spade electrode at said one position to cause an electron beam to form thereat.

4. The circuit defined in claim 2 wherein said discharge 55 device is a transistor having base, emitter, and collector electrodes, and including a bleeder network coupled from said cathode to a reference potential,

the collector electrode of said transistor being coupled .to a point on said bleeder network whereby an opsaid disabling means being operatively related to said bleeder network whereby it can affect said operating potential of said collector and can disable said transistor. v

5. The circuit defined in claim 2 wherein said discharge device is a transistor having base, emitter, and collector electrodes, and including a bleeder network coupled from said cathode to a reference potential,

said emitter electrode being coupled to a source of i reference potential, said base electrodebeing coupled 5 V. to the spade electrode at said oneposition in said tube, 1 v

a capacitor coupled to a portion of said blceder network and comprising a portion of said disabling means,

the collector electrode of said transistor being coupled to a point on said blceder network whereby an operating potential is applied thereto,

said capacitor controlling the potential of said point and of said collector electrode whereby the operation of said transistor is controlled.

6. The circuit defined in claim 2 wherein said discharge device is a transistor having base, emitter, and collector electrodes, and including a blceder network coupled from said cathode to a reference potential,

said emitter electrode being coupled to a source of reference potential, said base electrode being coupled to the spade electrode at said one position in said tube,

a capacitor coupled to a portion of said blceder network and comprising a portion of said disabling means,

the collector electrode of said transistor being coupled to a point on said blceder network whereby an operating potential is applied thereto,

said capacitor controlling the potential of said point and of said collector electrode whereby the operation of said transistor is controlled, and a pulse source coupled to the switching electrodes in said e tube for applying counting pulses thereto and causing an electron beam to switch from position to position therein.

7. Thecircuit defined in claim wherein said discharge device is a transistor having base, emitter, and collector electrodes, and including a blceder network coupled from said cathode to a reference potential,

said emitter electrode being coupled to a source of reference potential, said base electrode being coupled to the spade electrode at said one position in said tube,

a capacitor coupled to a portion of said blceder network and comprising a portion of said disabling means,

the collector electrode of said transistor being coupled to a point on said blceder network whereby an aperating potential is applied thereto,

said capacitor being charged to an operating potential while said tube performs a counting operation,

said capacitor being discharged when a beam is cleared and reset in said tube, said capacitor thus controlling the potential of said point and of said collector electrode whereby the operation of said transistor is controlled.

References fitted in the file of this patent UNITED STATES PATENTS 3,022,442 Glaser Feb. 20, 1962 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3,168 ,675 February 2, 1965 Arpad Somlyody It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, line 26, for "whtich" read which line 28, after "sep-" insert arate capacitors 29 to each of the auxiliary electrodes 22 line 33, for "and" read are same column 2, line 49, for "for" read from Signed and sealed this 6th day of July 1965.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Al testing Officer Commissioner of Patents 

1. A COUNTER CIRCUIT INCLUDING AN ELECTRON BEAM SWITCHING TUBE HAVING A CATHODE AND A PLURALITY OF GROUPS OF ELECTRODES; EACH GROUP INCLUDING A TARGET ELECTRODE WHICH RECEIVES AN ELECTRON BEAM AND PRODUCES AN OUTPUT SIGNAL THEREFROM, A SPADE ELECTRODE WITH HOLDS AN ELECTRON BEAM ON ITS ASSOCIATED TARGET ELECTRODE, AND A SWITCHING ELECTRODE WHICH SERVES TO SWITCH AN ELECTRON BEAM FROM ONE GROUP OF ELECTRODES TO THE NEXT; SAID CATHODE BEING CONNECTED TO A SOURCE OF REFERENCE POTENTIAL, SAID SPADE ELECTRODES BEING CONNECTED THROUGH RESISTIVE PATHS TO A SOURCE OF REFERENCE POTENTIAL, SAID TARGET ELECTRODES BEING COUPLED THROUGH RESISTIVE PATHS TO A SOURCE OF REFERENCE POTENTIAL, AND SAID SWITCHING ELECTRODES BEING CONNECTED TO A SOURCE OF SWITCHNG SIGNALS; ONE OF THE POSITIONS BEING SELECTED BOTH FOR THE TRANSMISSION OF A CARRY PULSE AT THE END OF A COUNTING CYCLE AND FOR THE RESETTING OF AN ELECTRON BEAM AFTER A BEAM HAS BEEN CLEARED AND IT IS DESIRED TO INITIATE A NEW COUNTING CYCLE; SIGNAL GENERATING MEANS COUPLED TO SAID ONE POSITION FOR GENERATING A CARRY PULSE WHEN AN ELECTRON BEAM REGISTERS A COUNT IN SAID ONE POSITION; AND MEANS COUPLED TO SAID SIGNAL GENERATING MEANS FOR DISABLING SAID SIGNAL GENERATING MEANS DURING A PULSE RESETTING OPERATION. 